If the officer has legal reason to search you, he doesn't need your consent.

if he doesn't, he pretty much has to ask you. It may not sound like a request (eg "I need to look in your bag."), but part of being a responsible, informed citizen is to know not only what your rights are, but when you can exercise them.

Seems to me this stop, question, and frisk business is just a riff on consensual searches.

__________________The US Air Force has started including tax protester literature in the emergency supplies of their aircraft. If the plane crashes in a remote area, the crew is instructed to read the pamphlets and Goalie will be along shortly to rebut them.